Cargo lift



1952 s. L.. SAXTON ET AL 2,581,887

CARGO LIFT Filed Dec; '7, 1949 5 Sheets-Sheet 1 STANLEY L. sAx roN STEPHEN E. Loweu.

M OMYW 1952 s. SAXTON ET AL 2,581,837

CARGO LIFT Filed Dec. 7, 1949 3 Sheets-Sheet 2 FIZZ 5'5 swam/bo a Srmmer 4. 54x7 STEPHEN 1 Lon/4.

1952 s. L. sAxToN ET AL 2,581,887

CARGO LIFT Filed Dec. 7, 1949 a Sheets-Sheet a FIE 5' 63 37-4045 4. S/mra/v 'STEP/IE/V E. Lon e24.

Hill IIH' h H Patented Jan. 8', 1952 CARGO LIFT StanI y L. Saxton and Stephen E. Lowell,

. v La CroSse Wis.

Application December 7, 1949, Serial No. 131,668

in construction and installation and-which lends itself to use either in the conventional stairwell in conjunction with the stairway therein, or to simple install ion be ween floors wherever space is available and if desired in conjunction. with trap doors in said floors. l

Another object of our invention is to provide a cargo lift embodying spaced rails secured to and between the floors to be served and a carriage travel mounted .on said rails for up and down movements by means of winch drums op erated by an electric motor and in turn operating cables by which the carriage is positioned. In

this regard the present lift and this application are related to the stairway elevator disclosed in our prior co-pending application Serial No. 69,868 filed January 8, 1949 now Patent- No. 2,516,726, dated July 25., 1950.

.A further and i rtant object is the provision of a ar o l ft o t s pe f sa ety means constituting a fail-safe mechanism whichuwill automatically and instantaneously lock the "carriageagainst downward movement sho dcables by which the carriage. is moved break or become slack f r other r ason. In accordan e w th his obiec weiur h r provi means operativ by said a l-safe m hanism to auto mat al y hut ofi po to the. motor driv n the cable winches, and operate said ailate .mechanism as well as the motor cut-oft svvlt ih i ec ly in resp n e to cable. tension 80 that th mevhanism will immediately sense. any failure an ing the carr ag to a top as well as stop he mo or- I A, fur er o i ct oi the invention. is to. provide a car o lift o h f regoing d scri ed nature. whe ein the operating mechanism i lud- Inc the mot r ca le w nches a d related parts are 7 a l arr dbeneath the pla orm o the carria and further o o construct the e irer raming as:

sembly that the "an le at which the'rsi are mounted a e varied to s it the requirements of each indi idual ins a ation with aminimum of'trouble and required c a ge-g. 1 itbejo all construction.

Intake. the form of conventional channelsjrig- I 11 Claims. (Grist-12) .do no of c urse, limit Still a further object of our invention is to providenumerous detailed improvements in the construction and operation of such devices, all of which contribute to the provision of a cargo lift which may be readily installed in many 10- cations where the use of -more conventional shaft type elevators would be utterly impossible.

These and other more detailed and specific objects will be disclosed in the course ofthe following specification reference being had to the accompanying drawings, in which:'

Fig. 1 is a side elevation of 'a cargo lift according .to our invention showing the same as arranged between two adjacent floors of the building and illustrating in dotted lines the uppermost and lowermost positions assumed by the carriage. g

Fig. 2 is. a front elevational view of the struc-- ture as shown in Fig. 1.

Fig. 3 is an enlarged vertical sectional view through the carriage and associated end adjacent parts of .the lift structure.

Fig. 4 is a fragmentary and irregular sectional viewv taken along the line 44 in Fig. 3.

Fig. 5 is an enlarged side elevation, partially in section, taken substantially along the line I 5--5 in Fig 2 and showing particularly the automatic lock or stop means for the carriage.

vertical wall CY.- So that the carriage of the lift in its lower position may be run down flush with the lower floor A, for the maximum convenience in loading, this floor is provided a pit D, while for delivery of materials to theupper floor B it is provided with an openingE, It will, of course, i0

be understood that this opening E may be coveredby conventionalautomatic trap doors for safety purposes and an important feature of our invention resides in the fact, as seen clearly in 1, that the installation of the lift requires or forms no obstruction above the level of the upper floor B, As stated, this illustration of the lift is purely for purposes of exemplification and V ourselves to this particular type of installation.

I Thecargo has as its primary supports a pair of transverse y spaced upright-and angularly positioned rails designated generally at Inwhich constitute a track along which. may travel a car- 'riage orcargo carrier indicated at H. The rails idly secured to convenient locations in the building and with the channels turned inwardly in facing relation to accommodate rollers upon the carriage II as will presently appear. The rails Ill are rigidly cross connected by tie bars I2 secured in place by angles I3 which so space the cross bars that toe room is provided between the carriage and the bars as the former moves up and down.

The carriage II comprises a rectangular platform I4 mounted upon angle iron sills I5 and cross bars I6 and from what may for convenience be termed the rear end of the platform there depends at each side angle iron side bars I'I secured at upper ends at I8 to the aforesaid sills.

At their lower ends these side bars I! are secured at I9 to brace bars which angle'from these points upwardly and forwardly to points of .at-

tachment at 2I to the sills I6 adjacent the for ward ends thereof. The side bars I 'I are located parallel with the rails I0 while the platform I4 is horizontally located and the brace bars 20 are, of course, selected as to length to so position the parts. Bearings 22 are secured to the rear faces of the side bar I! adjacent the upper and lower ends thereof and upper and-lower roller shafts 23 and 24 are extended transversely between these bearings to rotatably carry rollers indicated f throughout at 25, shaped and positioned to roll in the channels of the rails II}. It will, of course,'

be understood that the rollers 25-willthus support the carriage I I for up and down movements along the rails II! and in so doing the lower pair of rollers'will run in contact with the rear flanges of the rails while the upper pair will roll in engagement with the forward flanges.-

The carriage I I is moved up and down the rails and'positioned at any point therealong by means of an operating mechanism powered by a con- ,ventional reversible electric motor 26 secured at 21 to a hanger plate 28 mounted beneath the ,platform plate assembly I5-I6. The motor shaft 29 extends in a forward direction for con- 1 nection at 39 to a worm gear transmission unit 3| secured at 32 beneath the forward portion of After passing around these pulleys 39 and 40 the Y cables 3! and 38'run beneath and then upwardly around similar pulleys 43 and 44 journaled as indicated at 45 upon the rear surfaces of the side bar I7. The pulleys 43 and 44 thus guide the cables upwardly in the channels of the rails I0 outside of the uppermost rollers 25 and-at their upper ends the cables are secured to theupper ends of the rails as indicated at 46. Preferably these connections 46 are arranged to tighten and equalize the cables3'l and 38 in any well known manner; j 1

Itwill now be understood that the rotation of the winch drums 35 and 35 in one direction -Wll1 cause the cables 31 and 38 to be wound up pull the carriage II in an upward direction. Reverse rotation 0f the "drums will, of course, 'pay out the cables-in order'topermit the carriagev to descend of its 'own weight. It is to be noted I that the cables do not themselves move but that 4 the carriage in effect travels up and down on the cables and further since we use a worm gear drive that the carriage is self-locking in any position so long as the cables themselves are in good condition. The motor 26 may be conveniently controlled by a switch box 41 mounted at a convenient height upon one of the rails It! so that the motor may be started or reversed as may be required. Arranged in conjunction with the motor shaft 29'is a conventional solenoid brake assembly 48 operative when power to the motor is shut off to immediately stop the motor shaft and prevent overrunning of the carriage beyond the desired position. The motor is automatically out oil at the upper and lower limits of the carriage travel by means of limit switches 49 and 50 mounted upon one of the rails In and operative by rollers 5I which are engaged by adjustable contact brackets 52 and 53 secured at 54 to the side bar I1--as best shown in Fig. 3.

" Thus, as the' carriage levels with either the upper or lower floors, the power will be automatically shut 01? in order to level the platform I4 in loading or unloading positions.

The carriage frame also includes tie bars or angles 55 which are secured to the cross bar 42 and converge in a forward direction,- being secured at their forward ends at 56 to the trans- 'mission unit 3I. When the angle of the rails Ill is changed, the only carriage changes required in order to keep the platform I4 level, is a change in the length of these'tie bars 55 and the brace bars 20, as will be understood.

Current is supplied to the motor 23 through a conventional trolley arrangement consisting of a pair of enclosed and protected bus bars 51 secured by brackets 58 to one of the rails IQ and engaged by a travelling trolley 59 which is car'- jried by bracket 60 upon the carriage I I. Flexible conductors IiI lead from the trolley 61} to the motor'and this entire mechanism being entirely conventional in-constructi'on need not be further described herein. It will, of course, be understood further that a conventional reversing switch as indicated at 62 in Fig. 1 is employed in order to reverse the direction of rotation of the motor.

7 An important feature of our present invention resides in the provision of a fail-safe mechanism operative upon the failure of either cable 31 or 38 to immediately shutoff or stop the motor 26 and lock the carriage 'I I to both of the rails II]. This mechanism comprises a rock shaft 63 journaledacross the side bars I! in bearing bracket 54 and carrying sharply pointed dogs 65 at its outer ends.- These dogs are .thus aligned with the fo "ward surfaces of the rails I0 and they may be swungdownwardly and rearwardly from their normalpos'itions illustrated by dotted lines in Fig.5.bymeans of. a retractile coil spring 65 which'is stretched between the lower end of an arm 61 upon theshaft 63 and a finger I38 secured to the adjacent lower roller shaft 24. As shown in full lines in Fig. 5 this movement of the dog 54 by the spring 66 will cause the pointed ends of the dogs to bite into the facesof therails and 'positively lock thencarria'ge thereto against downward movement. The arm 61 also extends upwardly from the shaft 53 and is normally engaged by the hookedj forward end of a latch 69 which 1 [pivoted at Ill toa. bracket II carried by cross barsg'n connecting theside bars I I. When the latch 6918 t us. engaged "it will hold the; dog .165 clear of the rails to permit the desired upward and downward movements of the carriage.

and scope of the appended claims.

the latch is is condoned or "operated by mechanism which senses or is responsive to the 'tensioi'i ofthe cables 31 and 38, and "which com- ;prises an equalizing bar 13 positioned cross wise some distance from the latch, above the tie bars 55 previously described. Near the ends of the "equalizing bar 13 support rods 14 are secured in place and depend loosely down through suitable apertures in the tie bars 55 below which coil springs 15 are placed upon the rods in order to normally bias both ends of'the equalizing bar in a downward direction. The tension of the springs '15 may be adjusted by nuts 16 threaded upon the lower ends of the rods 14 and the tension is so adjusted that pulleys T1 journaled at the ends of the equalizing bar will'be engaged with the e'ables 31 and 38, between the'winch drums 35 and 36 andthe pulleys 39 and 49, with such force 'asto slightlybend the cables downward as they pas between these points. Thus it will be evident that so long as the cables 31 and 38 remain taut, the equalizing bar 13 will be held in an upper position but upon the failure of either cable the bar will be moved downwardly, at its center, by'the springs 15. This downward movenien't' of the equalizing bar is made use of by means of an actuating rod 18 to release the latch '58 and for this purpose the rod T8 extends downwardly into a position for engaging the rear end 'of the latch as indicated in Figs. 3 and 5. In the 7 normal position of the equalizing bar, however, the actuating bar 18 will-stand free of the latch -'-G9,'So that the latter will remain in engagement with the arm 61 in order to hold the dog 65 clear of the rails. The actuating rod 18 also depends througha motor cut off switch unit indicated at 79 which is secured to the cross bars 12 and connected incircuit .to the motor 26. As long .as the equalizing bar [3 remains in its normal elevated position the cut oifswitch 19 will be closed so as not to interfere with the normal starting and stopping of the motor. The switch is so constructed, however, that the downward movement of the actuating rod 18 when a cable failure occurs will immediately open the circuit to the motor bringing it to a halt,

It will now be understood that a cable failure will not only immediately engage the dogs'55' with the rails I0 in order to hold the carriage at any level at which such failure occurs, but

that the power to the motor will also be cut off concurrently in order to "prevent any damage to theparts. After each such operation of the failsafe mechanism it will, of course, be necessary to reset the same by manuallyre-engagingthe latch 69 after the cables have been repaired.

The safety mechanism'is thus seen to be notonly therefore fully illustrated and described our invention, what we claim to be new and desire to protect by Letters Patent is:

1. A cargo lift of the character described, comprising a pair of spaced upright rails, a carriage supported on the rails for travel upwardly and downwardly therealong, cables secured at the upper ends of the rails and extending therefrom down to the carriage, power operated drums on the carriage to wind up or pay out the cables Having now and thereby move the carriage up and down respectively, and safety means operated by the tautness of the cables to shut off the power to the drums when either cable slackens.

2. A cargo lift of the character described, comprising a pair of spaced upright rails, a carriage supported on the rails for travel upwardly and downwardly therealong, cables secured at the upper ends of the rails and extending therefrom down to the carriage, power operated drums on the carriage to windv up or' pay out the cables and thereby move the carriage. up and. down respectively; safety meansoperated by the tautness. of the cables to shutoff the'power to the drums when either cable slackens,- and stop engage the rails, a shaft on the carriage carrying said dogs and spring biased to normally engage the dogs "with the rails, latch meansoperative to hold thedogs clearof the rails, and means operated in response to cable tension to operate said latch means.

' 4. In a cargo liftofthe character described, a pair ofgenerally upright spaced rails, a carriage'having rollers engaging said rails, cables secured to the upper ends of the rails, a motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or pay out thecable whereby the carriage may descend, the improvement which comprises 'a fail-safe mechanism' including dogs adapted to engage the rails, a shaft on the carriage carrying said dogs and spring biased to normally engage the dogs with the rails, a latch operative to hold the dogs clear of the rails, and means including an equalizer mechanism engaging the cables for operating the latch and releasing same in responseto a decrease or failure in cable tension.

5.- In a cargo lift of the character described, apair of generally upright spaced rails, a car riage having rollers engaging said rails, cables secured to the upper ends of the rails, a motor operated winch mechanism on the carriage and operating the cables to'pull the carriage up the rails or pay out the-cable'whereby' the carriage may descend, the improvement which comprises a fail-safe mechanism including dogs adapted to engage the rails, a shaft on the carriage carrying said dogs and spring biased to normally engage the dogs with the rails, an arm on said shaft, a latch normally engaging the arm to hold the dogs clear of the rails, an equalizer bar supported on the carriage and having rollers engaging the cables, and means carried by the equalizer bar to trip and release the latch upon a failure of the cables.

6. In a cargo lift of the character described, a pair of generally upright spaced rails, a carriage having rollers engaging said rails, cables secured to the upper'ends of the rails, a motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or pay out the cable whereby the carriage may descend, the, improvement which comprises; a fail-safe mechanism including dogs adapted to engage'th rails,a shaft on the carriage carrying said dogs and spring biased to normally engage the dogs with the rails, an arm on the shaft, a latch normally engaging the arm to hold the dogs clear of the rails, a support'on the carriage, an equalizer barloosely mounted on the support and having an actuating rod for engaging'the latch, means biasing the equalizer bar downward to disengage the latch from the arm, and rollers on the equalizer bar resting on the cables and normally holding said actuating rod upward free of the latch. I

7. In a cargo lift of the character described, a 7

pair of generally upright spaced rails, a carriage having rollers engaging said rails, cables secured to the upper ends of the rails, a motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or i dogs clear of the rails, a, support on the carriage,

an equalizer bar loosely mounted on the support and having an actuating rod for 'engaging the l latch; means biasing the equalizer bar downward to disengage the latch from the arm, rollers on the equalizer bar resting on the cables and normally holding said actuating rod upward free of thelatch, and a motor cut-off switch operated by said actuating rod to stop the motor'as the latch is released.

8. Ina cargo lift of the character described, a pair of generally upright spaced rails, a carriage having rollers engaging said rails, cables secured to the upper ends of the rails, a'motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or pay out the cable whereby thecarriage may descend, the improvement which comprises a failsafe mechanism including dogs adapted to engage the rails, a shaft on thercarriage carrying said dogs and spring biased to normally engage the dogs with the rails, an arm on the shaft, a latch normally engaging the arm to hold the dogs clear of the rails, a support on the carriage, an equalizer bar loosely mounted on the support and having an actuating rod for engaging the latch, means at each end of the equalizer bar biasing the same in a downward direction to release said latch, and means on the ends of the equalizer bar resting on the cables to, hold the actuating rod in an upper position solong as the cables are both taut. V I

9. In a cargo lift of the character described, a pair of generally upright spaced rails, a carriage having rollers engaging said rails: cables secured to-the upper ends of the rails, a motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or pay out the cable whereby the carriage may descend, the improvement which comprises a solenoid brake on the motor to stop the winch mechanism when power to the motor is cut oif and prevent overrunning of the carriage. V

10. In a cargo lift of the character described, a pair of generally upright spacedrails, a carriage having rollers engaging said rails, cables secured to the upper ends of the rails,- a motor operated winch mechanism on the carriage and operating the cables to pull the carriage up the rails or pay out the cable whereby the carriage may descend; the improvement which comprises a fail-safe mechanism including dogs adapted to engage the rails, a shafton the carriage carrying said dogs, and meansconnected to said shaft and having grooved rollers-riding the cables operative when a cable loosens to'initiate movement of the shaft to set said dogs against the rails.

'11. In a cargo lift of the character described, a pair of generally upright spaced rails, a car,-

riage having rollers engaging said rails; cables operating the cables to pull the carriage up the rails or pay out the cable whereby the carriage may descend, the improvement which comprises a fail-safe mechanism including dogs-adapted'to REFERENCES CITED The following references are of record in the file of this patent: 1 1

UNITED STATES PATENTS Number Name Date 770,560 Cook -Sept. 20, 1904 844,947 Lowry Feb. 19, 1907 1,132,770 I Gale Mar. 23, 1915 "2,340,052 Grimes Jan. 25, 1944 2,408,808= Paulus et a1. Oct. 8, 1946 2,516,726 Saxton et al July 25, 1950 

